[...]... strongly, and becomes fluid again when exposed to the open air To this liquor the workmen have given the name of the mother of nitre; and Hoffman, finding it composed of the magnesia united to an acid, obtained a separation of these, either by exposing the compound to a strong fire in which the acid was dissipated and the magnesia remained behind, or by the addition of an alkali which attracted the acid... with the microscope, appear to be assemblages of needles diverging from a point This happens more especially when the solutions of the epsom-salt and of the alkali are diluted with too much water before they are mixed together Thus, if a dram of epsom-salt and of salt of tartar be dissolved each in four ounces of water, and be mixed, and then allowed to rest three or four days, the whole of the magnesia. .. taste, and shews only a very light cloud upon the addition of alkali.[4] The same white powder is also formed when spirit of vitriol is added to a calcarious earth dissolved in any other acid; the vitriolic expelling the other acid, and joining itself to the earth by a stronger attraction; and upon this account the magnesia of sea-water seems to be different from either of those described by Hoffman... D EXPERIMENTS UPON MAGNESIA ALBA, QUICKLIME, AND SOME OTHER ALCALINE SUBSTANCES; BY JOSEPH BLACK, M.D.[1] PART I one observations, Hoffman,theinhistoryofof hispowder called gives a magnesia alba, which had long been used and esteemed as a mild and tasteless purgative; but the method of preparing it was not generally known before he made it public.[2] It was originally obtained from a liquor called the. .. Geoffroy's table of elective attractions Three drams of magnesia in fine powder, an ounce of salt ammoniac, and six ounces of water were mixed together, and digested six days in a retort joined to a receiver During the whole time, the neck of the retort was pointed a little upwards, and the most watery part of the vapour, which was condensed there, fell back into its body In the beginning of the experiment,... salt was therefore collected in a dry form in the receiver, and afterwards dissolved into spirit When all was cool, I found in the retort a saline liquor, some undissolved magnesia, and some salt ammoniac crystallized The saline liquor was separated from the other two, and then mixed with the alkaline spirit A coagulum was immediately formed, and a magnesia precipitated from the mixture The magnesia. .. magnesia is still undissolved, and part of the calcarious earth remains yet joined to the acid When a small quantity of magnesia is thrown into a solution of the corrosive sublimate of mercury, it soon separates part of the mercury in the form of a dark red powder, and is itself dissolved Imagining that I perceived some resemblance between the properties of magnesia and those of alkalis, I was led to try... afterwards made use of a salt called epsom-salt, which is separated from the bittern by crystallization, and is evidently composed of magnesia and the vitriolic acid There is likewise a spurious kind of Glauber salt, which yields plenty of magnesia, and seems to be no other than the epsom salt of sea water reduced to crystals of a larger size And common salt also affords a small quantity of this powder;... not disagreeable, and it appears to be rather of the cooling than of the acrid kind Having thus given a short sketch of the history and medical virtues of magnesia, I now proceed to an account of its chemical properties By my first experiments, I intended to learn what sort of neutral salts might be obtained by joining it to each of the vulgar acids; and the result was as follows Magnesia is quickly... part of it is the neutral salt, formed from the union of the acid and alkali This neutral salt is found, upon examination, to agree in all respects with vitriolated tartar, and requires a large quantity of hot water to dissolve it As much of it is therefore dissolved as the water can take up; the rest is dispersed thro' the mixture in the form of a powder Hence the necessity of washing the magnesia with . alt="" The Project Gutenberg EBook of Experiments upon magnesia alba, Quicklime, and some other Alcaline Substances, by Joseph Black This eBook is for the use of anyone anywhere at no cost and with almost. or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www .gutenberg. net Title: Experiments upon magnesia alba, Quicklime, and some other Alcaline Substances Author:. D. EXPERIMENTS UPON MAGNESIA ALBA, QUICKLIME, AND SOME OTHER ALCALINE H SUBSTANCES; BY JOSEPH BLACK, M.D. [1] PART I. offman, in one of his observations, gives the history of a powder called magnesia